Field
Exemplary embodiments relate to performing heat exchange with combustion gas generated in a furnace of a thermal power plant, and more particularly, to a heat exchanger unit for more efficiently performing heat exchange by changing a heat exchange area with combustion gas or a flow thereof.
Description of the Related Art
In general, tubes for heat exchange are installed at the rear end of a furnace of a thermal power plant, and are used as a reheater for combustion air which is introduced into an absorption tower through heat exchange with combustion gas passing through the furnace.
A high-temperature fluid is moved into tubes, and exchanges heat with combustion air passing through a reheater, with the consequence that the temperature of the combustion air is relatively changed.
As the size of a furnace has been gradually increased in recent years, various errors and malfunction occur due to the use of low grade coal in a thermal power plant.
Heat exchanger fins in the form of spiral are conventionally installed in the longitudinal direction of tubes for the use thereof. However, the heat exchanger fins may disturb the stable flow of combustion air, and a large amount of ash contained in combustion may be stacked outside the fins.
For this reason, there are many problems in that the overall heat exchange performance of a reheater is deteriorated, and pressure drop is partially generated or heat transfer performance is deteriorated since combustion gas does not stably flow through a plurality of tubes.
[Patent Document 1] Korean Patent No. 10-0490722 (May 12, 2005)